AND MARSHY SITUATIONS. 131 



ceptlble effedl, except a flight giddinefs after (he had 

 dei'cended a flight of ftairs. 



No alteration is made in their properties by the mix- 

 ture of carbonic with hydrogenous g:is. No decompo- 

 fition takes place, no caloric is fet at liberty or heat ren- 

 dered fenfible by fuch union. We may therefore from 

 what has now been ftated, conclude that neither carbonic 

 nor hydrogen gas, hngly or combined is the miafma or 

 effluvium by which the diieaies in queftion are produced. 



In confecjuence ot the putrefaction of farinaceous plants, 

 and all fuch as abound more in gluten than in the faccha- 

 rine, or mucilaginous principles, as well as from the 

 putrefa£lion of animal fubftances, an ammoniacal gas 

 is produced, owing to the union of the hydrogen, evol- 

 ved in the putrefactive fermentation, with the fuperabun- 

 dant azote of the atmofphere.* But this gas inftead ot 

 diminilhing the powers of the human body, is well 

 known to have a contrary efi^sdl, except when received 

 into the lungs in a large quantity, and then it proves 

 deftiudtive from its ftimulating quality, inducing a fpafm 

 on the glottis or bronchiae. That neither the water of 

 marfhes, nor the exhalations which arifefrom thence, are 

 feptic or promoters of putrefadion, has been fully demon- 

 ftrated by the experiments of Dr. Alexander, -f- 



* Does the unkn of dead animal and vegetable fubftances prevent the 

 noxious effefts of each othti ? 



f Hi.ing filled a tea cup with putrid water taken trom a ditch in the 

 meadc ws on the fnuth fide of Edinburgh, (vvhicli in fummer conta-n a 

 confid'irable quantity of extremely putrid ftagnating watei), and another 

 cup \vith pure water, " 1 put a bit of irulton into eacli cup and let 

 them together in the open air. The mutton in t! e pure water began to 

 putrefy Inabout 36 hours. Attire end of three days,thitin the marfli water 

 was quite fweet. On the jih day it was taken out wafhed careiullv with 

 pure water, and found perfeifily fweet. That in the pure water was now 

 become intolerably fetid, and en that account was thrown away. The 

 7th day the mutton in the marlh water was vnllied again, and found 

 as trefh as before. When it had lain in about fix weeks, it itill rontinued 

 pcrleftly fweet, and the liquor around it of the fame fmell and colour as at 



firft 



